Nut Restrainer, and Methods of Use

ABSTRACT

In accordance with one or more embodiments of the invention, nut restrainers and methods of use are presented, particularly as they apply to high-strength bolted connections for steel structures. Nut restrainers may define a cavity that accepts insertion of a nut, and may include deformable or removable centering elements that allow the nut to move laterally to accept a bolt that is inserted non-concentrically with the nut restrainer, and may comprise a mobile central portion and a rigid outer portion; A method of positioning a nut restrainer concentric with a bolt hole accurate to within the radial tolerance of the bolt hole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. application Ser. No.16/846,283 filed on Apr. 11, 2020, now U.S. Pat. No. 11,519,451 issuedDec. 6, 2022, which is hereby incorporated by reference in its entiretyfor all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION Field of Invention

The invention disclosed herein generally relates to high strength boltedconnections. More specifically, the invention disclosed herein relatesto nut restrainers, and methods of use.

Description of Related Art

Use of high-strength bolted connections (including, for example, boltsconforming to ASTM F3125, nuts conforming the ASTM A563, and washersconforming to ASTM F436) is widespread in the construction industry tojoin steel elements of buildings, bridges and other structures. Boltedassembly is often preferred to the use of welding due to the simplicityand speed of installing bolts on a construction site. However, properinstallation of high-strength bolted connections typically requiresaccess to both sides of the parts being connected, making the use ofhigh strength bolts impossible in many cases. In other cases, engineersmay sacrifice material efficiency to facilitate the use of boltedconnections, for example, by using steel members with I-shapedcross-sections instead of those with more efficient box-shaped crosssections.

Nut restrainers, nut cages, and similar products have been widely usedin applications including sheet metal fabrication, but currentlyavailable nut restrainers have drawbacks that prevent wide adoptionwithin the steel constructions industry. First, many building codesinclude or reference prescriptive standards regarding the size, shape,and material properties of nuts, bolts, washers and holes, as well asspatial relations within the connection, methods of installation, andmethods of inspection. Hardware or practices that do not conform tothose prescriptive standards may require additional testing, approvalsand training to be used in conformance with the applicable buildingcode, thus increasing the cost to the installer. Thus, for any nutrestrainer to be widely adopted in the construction industry, it must becompatible with standard industry, hardware and practices.

Second, tolerances during structural member fabrication, and variabilityin the size and shape of structural members, either due to temperaturevariations or external forces imposed on the member at the time oferection, mean that a restrained nut must be able to accept a boltinserted non-concentrically with the nut. While several inventions havesought to address this issue using “floating nuts,” these inventionsgenerally include custom nuts or bolts, rather than being compatiblewith readily available hardware, severely limiting their adoption by theconstruction industry.

In the absence of nut restrainers well suited to the needs of theconstruction industry, several other products and practices exist toaddress the need for bolted connections when access is available fromone side only. However, all suffer from drawbacks when compared totypical high strength bolting. These include the following threeproducts and practices:

Welding a nut to the inaccessible side of the part in advance of siteassembly. This approach allows the bolt to be tightened from one sidebut violates standards commonly referenced by building codes, whichstate that nuts conforming to ASTM A563 shall not be welded. Thispractice also reduces installation tolerances by fixing the nut'slocation with respect to the bolt hole.

Blind bolts, which come in a variety of proprietary and non-proprietaryforms, can be installed and tightened from one side, but generally havesmaller allowable load-carrying capacities than traditional highstrength bolted connections. Blind bolts are generally more complex andexpensive than high strength bolts, and typically cannot be used inconnections where the bolt must tightly clamp the pieces of steel beingjoined, also known as slip critical connections.

Tapped holes have threads cut into the interior of the hole in thematerial on the inaccessible side. This approach requires highprecision, increases fabrication time, reduces installation tolerances,and typically cannot be used in connections where the bolt must tightlyclamp the pieces of steel being joined.

The existence of a product that allowed for the installation of highstrength bolted connections from one side at low cost, withoutreductions in load-carrying capacity, and while preserving installationtolerances, would allow more efficient structures to be erected at alower cost than is possible with current practice.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

In accordance with one or more embodiments of the invention, nutrestrainers and methods of use are disclosed. Certain aspects include anut restrainer for inserting a nut within the nut restrainer andthereafter affixing the nut restrainer to a substrate plate having twosides, over a bolt hole having a radial tolerance, for subsequentinstallation of a bolt having a shank and a tip, from the side of thesubstrate plate opposite the side to which the nut restrainer isaffixed, the nut restrainer comprising: a portion of one or morematerials formed to define a cavity, and including a top plane disposedaway from the substrate plate, and an open end; the cavity configured toaccept insertion of a nut, with the one or more materials formed todefine the cavity shaped to rotationally restrain the nut, and toinclude at least one location from which the nut has freedom of movementin any lateral direction equal to at least two times the radialtolerance of the bolt hole; the nut restrainer including one or more nutcentering elements comprising one or more portions of removable ordeformable material which extend into the cavity, and which areconfigured to hold the nut in a location from which the nut has freedomof movement in any lateral direction substantially equal to at least twotimes the radial tolerance of the bolt hole, and which may be removed ordeformed so as to no longer extend into the cavity following affixmentof the nut restrainer to the substrate plate, thereby allowing the nutmove in any lateral direction to accept the bolt if the bolt is insertednon-concentrically with respect to the nut; where the nut restrainer isconfigured to prevent escape of the nut from the cavity followingaffixment to the substrate plate; and where no portion of the nutrestrainer prevents direct contact between the nut and the substrateplate, or between the shank of the bolt and either the substrate plateor one or more fastened plates.

Some aspects include a nut restrainer for inserting a nut within the nutrestrainer and thereafter affixing the nut restrainer to a substrateplate having two sides, over a bolt hole having a radial tolerance, forsubsequent installation of a bolt having a shank and a tip, from theside of the substrate plate opposite the side to which the nutrestrainer is affixed, the nut restrainer comprising: one or more rigidouter portions and a mobile central portion; the mobile central portionformed to define a cavity, and including a top plane disposed away fromthe substrate plate, and an open end; the cavity configured to acceptinsertion of a nut, with the material of the mobile central portion thatdefines the cavity shaped to rotationally restrain the nut; the one ormore rigid outer portions, which include the portions of the nutrestrainer that are affixed to the substrate plate, configured so thatthe mobile central portion has freedom of movement in any lateraldirection substantially equal to at least two times the radial toleranceof the bolt hole; the one or more rigid outer portions and the mobilecentral portion being connected by one or more flexible connectors,which are sufficiently stiff and strong to substantially preventmovement of the mobile central portion in all lateral directions whenone or more of the nut and the mobile central portion are acted on byforces in any lateral direction with magnitudes not exceeding themagnitude of the force acting on the respective element due to gravity,and sufficiently strong to rotationally restrain the mobile centralportion when the mobile central portion is acted on by a torque due tothe action of tightening the bolt with the nut, and sufficientlyflexible to deform when the nut is acted on by a force in a lateraldirection due to contact between the tip of the bolt and the nut,thereby allowing the nut to move in a lateral direction to accept thebolt if the bolt is inserted non-concentrically with respect to the nut;where the nut restrainer is configured to prevent escape of the nut fromthe cavity following affixment to the substrate plate; and where noportion of the nut restrainer prevents direct contact between the nutand the substrate plate, or between the shank of the bolt and either thesubstrate plate or one or more fastened plates.

Some aspects include a nut restrainer for inserting a nut within the nutrestrainer and thereafter affixing the nut restrainer to a substrateplate having two faces, over a bolt hole having a radial tolerance, forsubsequent installation of a bolt having a shank and a tip, from theside of the substrate plate opposite the side to which the nutrestrainer is affixed, the nut restrainer comprising: one or more rigidouter portions and a mobile central portion; the mobile central portionformed to define a cavity, and including a top plane disposed away fromthe substrate plate, and an open end; the cavity configured to acceptinsertion of a nut, with the material of the mobile central portion thatdefines the cavity shaped to rotationally restrain the nut; the mobilecentral portion further having one or more radial protrusions whichextend away from the cavity; the one or more rigid outer portions, whichinclude the portions of the nut restrainer that are affixed to thesubstrate plate, having one or more deformable protrusions, each havinga tip; the deformable protrusions configured so that the tips of thedeformable protrusions maintain contact with the mobile central portionprior to insertion of the bolt, and hold the mobile central portion in alocation from which the mobile central portion has freedom of movementin any lateral direction substantially equal to at least two times theradial tolerance of the bolt hole; the deformable protrusions furtherbeing sufficiently stiff and strong to substantially prevent movement ofthe mobile central portion in all lateral directions when one or more ofthe nut and the mobile central portion are acted on by forces in anylateral direction with magnitudes not exceeding the magnitude of theforce acting on the respective element due to gravity, and beingsufficiently flexible to deform when the nut is acted on by a force in alateral direction due to contact between the tip of the bolt and thenut, thereby allowing the nut to move in a lateral direction to acceptthe bolt if the bolt is inserted non-concentrically with respect to thenut; the rigid outer portions further having one or more raised elementsthat are free from contact with the substrate plate, the space betweenthe raised elements and the substrate plate forming one or morerecesses; the recesses and the radial protrusions of the mobile centralportion being configured so that the radial protrusions fit into therecesses, and so that the mobile central portion is rotationallyrestrained in the counter-clockwise direction when viewed in a directionproceeding from the top plane to the open end, and so that the mobilecentral portion is prevented from moving away from the face of thesubstrate plate; where the nut restrainer is configured to preventescape of the nut from the cavity following affixment to the substrateplate; and where no portion of the nut restrainer prevents directcontact between the nut and the substrate plate, or between the shank ofthe bolt and either the substrate plate or one or more fastened plates.

Some aspects include a method of positioning the nut restrainerconcentrically with the bolt hole in the substrate plate accurate towithin the radial tolerance of the bolt hole, the method comprising:inserting the nut into the nut restrainer; placing the open end of thenut restrainer in flush contact with the substrate plate, therebypreventing removal of the nut; inserting a bolt from the side of thesubstrate plate opposite the nut restrainer, through the bolt hole, andbinding the bolt with the nut previously inserted into the nutrestrainer, so that the bolt and the nut are in snug contact with thesubstrate plate; affixing the nut restrainer to the substrate plate;removing the bolt from the nut and withdrawing the bolt from the bolthole in the substrate plate.

Some aspects include where the cavity is configured to accept insertionof a washer in addition to accepting insertion of the nut, and toprovide the washer freedom of movement in any lateral direction at leastequal to the radial tolerance of the bolt hole, and to prevent escape ofthe washer following affixment to the substrate plate. Some aspectsfurther include where the nut restrainer is configured so that the nutis visible from outside the nut restrainer following affixment to thesubstrate plate. Some aspects further include where the cavity defines asubstantially equiangular hexagon, and other aspects include where thecavity defines a substantially regular hexagon.

Some aspects include where the nut centering elements are sufficientlystiff and strong to substantially prevent movement of the nut in alllateral directions when the nut is acted on by a force in any lateraldirection with a magnitude not exceeding the magnitude of the forceacting on the nut due to gravity, and sufficiently flexible to deformwhen the nut is acted on by a force in a lateral direction due tocontact between the tip of the bolt and the nut, thereby allowing thenut to move in a lateral direction within the nut restrainer to acceptthe bolt when the bolt is inserted non-concentrically the nut.

Some aspects include where the nut restrainer includes one or morewasher centering elements, the washer centering elements comprising: oneor more portions of deformable material, which extend into the cavity ofthe nut restrainer; and hold the washer substantially concentric withthe nut restrainer; the washer centering elements being sufficientlystiff and strong to substantially prevent movement of the washer in alllateral directions when the washer is acted on by a force in any lateraldirection with a magnitude not exceeding the magnitude of the forceacting on the washer due to gravity, and sufficiently flexible to deformwhen the washer is acted on by a force in a lateral direction due tocontact between the tip of the bolt and the washer, thereby allowing thewasher to move in a lateral direction to accept the bolt if the bolt isinserted non-concentrically with respect to the washer.

Some aspects include where the nut centering elements are made of one ormore of foam, cork, rubber, plastic and felt, and the balance of the nutrestrainer is made of metal. Some aspects further include where the nutcentering elements are contiguous with the balance of the nutrestrainer, and the nut centering elements' deformability isattributable to their form and proportioning. Some aspects furtherinclude where the nut centering elements are attached to the balance ofthe nut restrainer using adhesive. Some aspects further include wherethe nut centering elements are attached to the balance of the nutrestrainer by snapping one or more portions of material that include thenut centering elements into place.

Some aspects include where affixment of the nut restrainer to thesubstrate plate is by means of welding. Some aspects further includewhere the top plane includes a hole to allow the tip of the bolt to passthrough the top plane after passing through the nut. Some aspectsfurther include where the top plane includes a hole to allow the tip ofthe bolt to pass through the top plane after passing through the nut,the hole being shaped to bind with the one or more portions of materialincluding the nut centering elements, and limit attachment of the one ormore portions of material including the nut centering elements to aposition from which the nut centering elements hold the nut in aposition from which the nut has freedom of movement in any lateraldirection substantially equal to at least two times the radial toleranceof the bolt hole.

Some aspects include where the raised elements and the deformableprotrusions are distinct portions of material. Some aspects furtherinclude where the raised elements and the deformable protrusionscomprise the same portions of material. Some aspects further includewhere the one or more rigid outer portions are made of metal, and themobile inner portion is made of plastic.

Definitions

Central axis: Unless otherwise defined for a specific element, a lineperpendicular to the substrate plate and passing through the center ofrotational symmetry of referenced element (nut, fastening bolt, orsubstrate bolt hole). The presence of helical threads in a referencedelement shall be ignored when determining the center of rotationalsymmetry.

Deformable Material: A material that is flexible or weak compared to thebalance of the nut restrainer, and which may deform in response to theinsertion of a bolt.

Direct Contact: Contact between two elements with no interveningmaterial.

Downward View: Refers to a view looking towards the face of thesubstrate plate to which the nut restrainer is affixed, at an angleperpendicular to the face of the substrate plate.

Equilibrium location: Location of an element (nut, washer, or mobilecentral portion) when no force external to the nut restrainer is actingon the respective element, or, in the case of the mobile centralportion, the element and its contents.

Escape: phenomenon whereby a referenced element ceases to be locatedwithin a second referenced element without being intentionally removed.

Final Configuration: The relative locations and internal forces anddeformations characteristic of the nut restrainer, its constituentparts, hardware, substrate plate, and fastened plates following theinstallation and tightening of the fastening bolt.

Freedom of movement: A condition characterized by a lack of materialincluded as part of the nut restrainer, that would by its presence,prevent the translation of the center of the referenced element (nut,washer, or a mobile central portion) in one or more specifieddirections. Freedom of movement may be bounded by the presence ofmaterial included as part of the nut restrainer that prevents thereferenced element from moving beyond set limits. Where freedom ofmovement is said to be equal to a certain value in one or moredirections, that value indicates the distance the referenced element maymove from a specified initial location until contacting a portion of thenut restrainer that is not deformable or removable. If no initialposition is specified, the initial position shah be considered to be theposition occupied by the referenced element at the moment of affixmentto the substrate plate. In embodiments that include one or more ofdeformable nut centering elements, removable nut centering elements,washer centering elements, flexible connectors, deformable protrusions,and raised deformable hold-downs, those elements shall not be consideredto prevent the translation of the referenced element.

Hardware: Nuts, washers, and bolts, typically in readily availablesizes.

Extending Into The Cavity: A state applicable to deformable nutcentering elements, removable nut centering elements, or washercentering elements, whereby portions of the respective centeringelements are collocated with portions of the cavity.

Lateral Direction: Any direction that is substantially parallel to theface of the substrate material to which the nut restrainer is affixed.

Cavity: Space surrounded or partially surrounded by material comprisingthe nut restrainer, in which no material comprising the nut restraineris present, with the exception of any nut centering elements or washercentering elements, in embodiments that include nut centering elementsor washer centering elements.

Nut Space: Portion of the cavity that accepts insertion of the nut. Inembodiments that lack a washer space, the nut space and cavity areidentical.

Nut Space Sidewalls: Portions of the nut restrainer surrounding orpartially surrounding the nut space, which rotationally restrain thenut.

Radial Tolerance Of The Bolt Hole: A scalar quantity of length equal tothe difference of the radius of a bolt hole and the radius of a boltthat is to be inserted into the bolt hole.

Regular Hexagon: Equiangular equilateral hexagon

Restrainer Central Axis: Line perpendicular to the substrate plate andpassing through the centroid of the cavity.

Rotationally Restrain: Prevent the rotation of the referenced element(the nut or the mobile central portion) beyond a finite angular limit.

Snug contact: State whereby internal stresses within one or more of aplurality of referenced elements cause the elements to exert force oneach other that tends to immobilize the referenced elements relative toeach other, the exerted forces being small enough that the referencedelements can be moved relative to each other by a person without the useof tools.

Substantially Prevent Movement: limit movement of a referenced elementdue to a referenced force to a distance that has no deleterious effecton the function of the nut restrainer.

Washer Space: Substantially cylindrical portion of the cavity thataccepts insertion of the washer.

Washer Space Sidewalls: Portions of the nut restrainer surrounding orpartially surrounding the washer space.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventions disclosed herein are nut restrainers and methods of usethat allow for the installation of bolted connections with access fromonly one side by confining the nut within a nut restrainer that isaffixed (by way of nonlimiting example, in some embodiments welded) tothe substrate material in advance of erection of structures including insome embodiments steel.

FIGS. 1, 2, and 3 show various views of exemplary embodiments of theinvention. FIGS. 1 a and 1 b show three-dimensional views of anembodiment in isolation, and FIG. 1 c shows a three-dimensional view ofan embodiment similar to the embodiment shown in FIGS. 1 a and 1 b butwith portions of material removed to make the contents of the restrainervisible, FIGS. 2 and 3 show other views of the embodiment shown in FIGS.1 a and 1 b.

FIG. 2 shows downward and cross sectional views of an embodiment of theinvention. In FIGS. 2 a, 2 b, 2 d and 2 f , the embodiment is shown withhardware included, whereas in FIGS. 2 c and 2 e , the embodiment isshown in isolation.

FIG. 3 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 3 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 3 b shows the embodiment after installation of thefastening bolt.

FIGS. 4, 5, and 6 show various views of an exemplary embodiment of theinvention. FIGS. 4 a and 4 b show three-dimensional views of theembodiment in isolation.

FIGS. 4 c and 4 d show elements of the embodiment in isolation topresent aspects of the embodiment that are not easily visible when theembodiment is shown in its entirety.

FIG. 5 shows downward and cross sectional views of an embodiment of theinvention. FIG. 5 a shows a downward view of the embodiment inisolation. FIG. 5 b shows a downward view of the embodiment withhardware included and the cap omitted, FIGS. 5 c, 5 d and 5 e show crosssections of the embodiment with hardware included.

FIG. 6 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 6 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 6 b shows the embodiment after installation of thefastening bolt.

FIGS. 7, 8 and 9 show various views of an exemplary embodiment of theinvention. FIGS. 7 a and 7 b show three-dimensional views of theembodiment in isolation.

FIGS. 7 c and 7 d show elements of the embodiment in isolation topresent aspects of the embodiment that are not easily visible when theembodiment is shown in its entirety.

FIG. 8 shows downward and cross sectional views of an embodiment of theinvention. FIG. 8 a shows a downward view of the embodiment inisolation. FIG. 8 b shows a downward view of the embodiment withhardware included and the cap omitted. FIGS. 8 c, 8 d and 8 e show crosssections of the embodiment with hardware included.

FIG. 9 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 9 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 9 b shows the embodiment during installation ofthe fastening bolt. FIG. 9 c shows the embodiment after installation ofthe fastening bolt.

FIGS. 10, 11 and 12 show various views of an exemplary embodiment of theinvention. FIGS. 10 a and 10 b show three-dimensional views of theembodiment in isolation.

FIG. 11 shows downward and cross sectional views of an embodiment of theinvention. FIG. 11 a shows a downward view of the embodiment inisolation. FIGS. 11 b, 11 c, 11 d and 11 e show cross sections of theembodiment with hardware included.

FIG. 12 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 12 a shows the embodiment at the moment of affixment tothe substrate plate. FIGS. 12 b and 12 c show the embodiment afterinstallation of the fastening bolt.

FIGS. 13, 14 and 15 show various views of exemplary embodiments of theinvention. FIGS. 13 a and 13 b each show a three-dimensional view of anembodiment of the invention in isolation. FIGS. 14 and 15 show otherviews of the embodiment shown in FIG. 13 a.

FIG. 14 shows downward and cross sectional views of an embodiment of theinvention. FIG. 14 a shows a downward view of the embodiment withhardware included. FIGS. 14 b, 14 c, and 14 d show cross sections of theembodiment with hardware included.

FIG. 15 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 15 a shows the embodiment at the moment of affixment tothe substrate plate. FIG. 15 b shows the embodiment after installationof the fastening bolt.

FIGS. 16, 17 and 18 show various views of an exemplary embodiment of theinvention. FIGS. 16 a and 16 b show three-dimensional views of theembodiment in isolation. FIGS. 16 c and 16 d show elements of theembodiment in isolation to present aspects of the embodiment that arenot easily visible when the embodiment is shown in its entirety.

FIG. 17 shows downward and cross sectional views of an embodiment of theinvention with hardware included. FIG. 17 a shows a downward view of theembodiment with hardware included. FIGS. 17 b and 17 c show crosssections of the embodiment with hardware included.

FIG. 18 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 18 a shows the embodiment at the moment of affixment tothe substrate plate. FIG. 18 b shows the embodiment after installationof the fastening bolt.

FIG. 19 shows various views of exemplary embodiments of the invention.

FIG. 19 a shows a three-dimensional view of two joined nut restrainersin isolation according to embodiments of the invention. FIG. 19 b showsa three-dimensional view of an embodiment in isolation. FIGS. 19 c and19 d show elements of the embodiment shown in its entirety in FIG. 19 bin isolation to present aspects of the embodiment that are not easilyvisible when the embodiment is shown in its entirety.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIGS. 1, 2, and 3 show various views of exemplary embodiments of theinvention. FIGS. 1 a and 1 b show three-dimensional views of anembodiment in isolation, and FIG. 1 c shows a three-dimensional view ofan embodiment similar to the embodiment shown in FIGS. 1 a and 1 b butwith portions of material removed to make the contents of the restrainervisible. FIGS. 2 and 3 show other views of the embodiment shown in FIGS.1 a and 1 b. FIG. 1 a shows a three-dimensional view of nut restrainer101 from the top and side. The embodiment shown in FIG. 1 a includes ahole in top plane 102 that is located and dimensioned to allow the tipof fastening bolt 126 (shown in at least FIG. 3 b ) to pass through topplane 102 in cases where fastening bolt 126 extends past nut 120 (shownin at least FIG. 3 b ) in the final configuration, as shown in FIG. 3 b. Nut restrainer 101 in this and other figures is depicted with sharpcorners and edges for visual clarity, though production versions wouldlikely have filleted corners and edges to facilitate manufacturing.

FIG. 1 b shows a three-dimensional view of nut restrainer 101 from thebottom and side. The embodiment shown in FIG. 1 b includes rectangularprism-shaped deformable nut centering elements 105 affixed to everyother side of hexagonally shaped nut space sidewalls 103. Deformable nutcentering elements 105 are configured to hold nut 120 (shown in at leastFIG. 3 b ) substantially concentric with nut restrainer 101 prior toinsertion of fastening bolt 126 (shown in at least FIG. 3 b ).Deformable nut centering elements 105 are formed and proportioned to beflexible compared to the balance of nut restrainer 101, allowing nut 120to move in any lateral direction to accept fastening bolt 126 (shown inat least FIG. 3 b ) if fastening bolt 126 is inserted non-concentricallywith nut restrainer 101. As shown in FIG. 1 b, deformable nut centeringelements 105 can be made of a variety of materials including but notlimited to foam, rubber, cork, or felt. In some embodiments, deformablenut centering elements 105 may be contiguous with the balance of nutrestrainer 101, such as in the embodiment shown in FIGS. 10, 11 and 12 .The relative locations of top plane 102, and washer space sidewall 104,are also shown.

FIG. 1 c shows a three-dimensional view of nut restrainer 101 from thebottom and side. FIG. 1 c is identical to FIG. 1 b, except thatexemplary viewports 107 are shown. Viewports 107 are not required forproper functioning of nut restrainer 101, but have two main benefits.First, viewports 107 allow for visual confirmation of the presence orabsence of nut 120 (shown in at least FIG. 3 b ), and washer 121 (shownin at least FIG. 3 b ), if present, following affixment of nutrestrainer 101 to substrate plate 122 (shown in at least FIG. 3 b ).Second, viewports 107 reduce the amount of material required to producenut restrainer 101. The relative locations of top plane 102, nut spacesidewalls 103, and washer space sidewalls 104, and deformable nutcentering elements 105 are also shown.

FIG. 2 shows downward and cross sectional views of an embodiment of theinvention. In FIGS. 2 a, 2 b, 2 d and 2 f , the embodiment is shown withhardware included, whereas in FIGS. 2 c and 2 e , the embodiment isshown in isolation. FIG. 2 a shows a downward view of nut restrainer 101with nut 120 included. The relative locations of top plane 102, nutspace sidewalls 103, and restrainer central axis 130 are also shown. Thelocation of section cut plane A is shown in FIG. 2 a , and is used insubsequent figures to identify the orientation of particularcross-sectional views. As shown in FIG. 2 a , and all subsequentfigures, hidden lines are indicated with uniform dashes, and centerlinesare indicated with alternating long-short dashes.

FIG. 2 b shows a downward cross-sectional view of nut restrainer 101with washer 121 included. The cross section shown in FIG. 2 b is cutthrough washer space sidewalls 104 of nut restrainer 101. The relativelocation of restrainer central axis 130 is also shown. The location ofsection cut plane A is shown in FIG. 2 b , and is used in subsequentfigures to identify the orientation of particular cross-sectional views.

FIG. 2 c shows a downward cross-sectional view of nut restrainer 101 inisolation. The cross section shown in FIG. 2 c is cut through nut spacesidewalls 103 and deformable nut centering elements 105 of nutrestrainer 101. As shown in FIG. 2 c , the cross-section of nut spacesidewalls 103 is an equiangular hexagon with unequal lengths, such thatsome sides of nut space sidewalls 103 are more distant from restrainercentral axis 130 than others. Deformable nut centering elements 105 areaffixed (by way of non-limiting example, in some embodiments usingadhesive) to the more distant sides of the hexagon to provide sufficientclearance for nut 120 (shown in at least FIG. 2 d ) to move in anylateral direction a distance substantially equal to at least two timesthe radial tolerance of the bolt hole without requiring deformable nutcentering elements 105 to compress to zero thickness. The relativelocation of cavity 133 is also shown. The location of section cut planeA is shown in FIG. 2 c , and is used in subsequent figures to identifythe orientation of particular cross-sectional views.

FIG. 2 d shows a downward cross-sectional view of nut restrainer 101with nut 120 inserted. The cross section shown in FIG. 2 d is cutthrough nut space sidewalls 103 and deformable nut centering elements105 of nut restrainer 101. As shown in FIG. 2 d , nut space sidewalls103 and deformable nut centering elements 105 are configured so thatdeformable nut centering elements 105 undergo compressive strain uponinsertion of nut 120 (said strain is visible in FIG. 2 d as a reductionin thickness of deformable nut centering elements 105 when compared toFIG. 2 c .), thereby ensuring that nut 120 is in snug contact withdeformable nut centering elements 105, and is substantially coaxial withnut restrainer central axis 130, even in cases where manufacturinginaccuracies result in non-nut space sidewalls 103 being larger thantheir theoretical dimensions, or in cases where manufacturinginaccuracies result in nut 120 being smaller than its theoreticaldimensions. As shown in FIG. 2 d , deformable nut centering elements 105are sufficiently stiff and strong to hold nut 120 concentric with nutrestrainer 101 when no force acting on nut 120 in a lateral directionexceeds the magnitude of the force imposed on nut 120 by gravity. Incases where fastening bolt 126 (shown in at least FIG. 3 b ) is insertedinto nut restrainer 101 non-concentrically with nut restrainer 101,interaction between the tip of fastening bolt 126 and nut 120 will causenut 120 to move in a lateral direction, further compressing one or moredeformable nut centering elements 105, and allowing fastening bolt 126to be tightened with nut 120. The location of section cut plane A isshown in FIG. 2 d , and is used in subsequent figures to identify theorientation of particular cross-sectional views.

FIG. 2 e shows a transverse cross-sectional view of nut restrainer 101in isolation. The location and direction of the cross sectional viewthrough nut restrainer 101 shown in FIG. 2 e is indicated by section A,as shown in at least FIG. 2 a . The relative locations of top plane 102,nut space sidewalls 103, washer space sidewalls 104, deformable nutcentering elements 105, and restrainer central axis 130 are shown.

FIG. 2 f shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 2 f isindicated by section A, as shown in at least FIG. 2 a . The relativelocations of top plane 102, nut space sidewalls 103, washer spacesidewalls 104, deformable nut centering elements 105, and restrainercentral axis 130 are also shown.

FIG. 3 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 3 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 3 b shows the embodiment after installation of thefastening bolt. FIG. 3 a shows a transverse cross-sectional view of nutrestrainer 101 and other relevant elements at the moment of affixment tosubstrate plate 122. The location and direction of the cross sectionalview through nut restrainer 101 shown in FIG. 3 a is indicated bysection A, as shown in at least FIG. 2 a . As shown in FIG. 3 a , theshank of centering bolt 125 is in contact with the walls of substratebolt hole 123, so that substrate bolt hole central axis 131 andrestrainer central axis 130 are offset by a distance substantially equalto the radial tolerance of the bolt hole. In some embodiments, centeringbolt 125 and fastening bolt 126 (shown in at least FIG. 3 b ) may be thesame bolt. However, in other cases, the lengths of threaded andunthreaded portions (if present) of the shank of fastening bolt 126 mayprevent fastening bolt 126 from being brought into snug contact with nut120 in the absence of fastened plate 124 (shown in at least FIG. 3 b ),necessitating the use of a distinct bolt as centering bolt 125. Therelative locations of top plane 102, deformable nut centering elements105, and washer 121 are also shown.

FIG. 3 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 3 b is indicated by section A, as shown inat least FIG. 2 a . As shown in FIG. 3 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, the nut space must provide freedom ofmovement to the nut substantially equal to at least two times the radialtolerance of the bolt hole in all lateral directions, and deformable nutcentering elements 105 must be formed and proportioned to remainflexible when deformed by a distance up to two times the radialtolerance of the bolt hole. The relative locations of top plane 102, nut120, washer 121, and substrate plate 122, are also shown.

FIGS. 4, 5, and 6 show various views of an exemplary embodiment of theinvention, FIGS. 4 a and 4 b show three-dimensional views of theembodiment in isolation. FIGS. 4 c and 4 d show elements of theembodiment in isolation to present aspects of the embodiment that arenot easily visible when the embodiment is shown in its entirety. FIG. 4a shows a three-dimensional view of nut restrainer 101 from the top andside. The relative locations of top plane 102, and cap 108 are shown.

FIG. 4 b shows a three-dimensional view of nut restrainer 101 from thebottom and side. Cap 108 as shown in FIG. 4 b is removable and includesremovable nut centering elements 106 that extend into the cavity of nutrestrainer 101 to hold nut 120 (shown in at least FIG. 6 b )substantially concentric with nut restrainer 101 until nut restrainer101 has been affixed to substrate plate 122 (shown in at least FIG. 6 b). Following affixment of nut restrainer 101 to substrate plate 122, andprior to insertion of fastening bolt 126 (shown in at least FIG. 6 b ),cap 108 is removed, thereby allowing nut 120 to move laterally withinthe nut space to accept fastening bolt 126 if fastening bolt 126 isinserted non-concentrically with nut restrainer 101. The relativelocations of top plane 102, nut space sidewalls 103, washer spacesidewalls 104, and snap-on protrusions 109 are also shown.

FIG. 4 c shows a three-dimensional view of nut restrainer 101 (shown inits entirety in at least FIG. 4 a ) from the top and side with cap 108(shown in at least FIG. 4 d ) not present. As shown in FIG. 4 c , someinterior edges of top plane 102 are filleted to allow snap-onprotrusions 109 (shown in at least FIG. 4 d ) of cap 108 to be easilysnapped into place atop nut restrainer 101. The relative locations ofnut space sidewalls 103, and washer space sidewalls 104 are also shown.

FIG. 4 d shows a three-dimensional view of cap 108 in isolation from thebottom and side. As shown in FIG. 4 d , cap 108 has at least fourcritical features: first, removable nut centering elements 106 aredimensioned and arranged to engage with at least three sides of nut 120(shown in at least FIG. 6 b ), holding nut 120 concentric with nutrestrainer 101 (shown in its entirety in at least FIG. 4 a ) until nutrestrainer 101 has been affixed to substrate plate 122 (shown in atleast FIG. 6 b ). Second, snap-on protrusions 109 are configured so thatcap 108 may be snapped into place atop nut restrainer 101, engaging withtop plane 102 (shown in at least FIG. 4 c ), Third, top plane 102 andsnap-on protrusions 109 are configured to ensure that cap 108 may onlybe snapped into place in a position that restrains nut 120 substantiallyconcentric with nut restrainer 101. Fourth, the tips of cap 108 extendbeyond the edges of nut restrainer 101 to allow removal of cap 108 byhand following affixment of nut restrainer 101 to substrate plate 122.

FIG. 5 shows downward and cross sectional views of an embodiment of theinvention. FIG. 5 a shows a downward view of the embodiment inisolation. FIG. 5 b shows a downward view of the embodiment withhardware included and the cap omitted. FIGS. 5 c, 5 d and 5 e show crosssections of the embodiment with hardware included. FIG. 5 a shows adownward view of nut restrainer 101 including cap 108. As shown in FIG.5 a , removable nut centering elements 106 are in flush contact with theinterior face of nut space sidewalls 103. Embodiments of the inventionwhere removable nut centering elements 106 are not in contact with aninterior face of nut space sidewalls 103 are also envisioned, thoughsuch an embodiment would have larger overall dimensions and thus largermaterial demands than the embodiment of nut restrainer 101 as shown inFIG. 5 a . Snap-on protrusions 109 and restrainer central axis 130 arealso shown. The location of section cut plane B is shown in FIG. 5 a ,and is used in subsequent figures to identify the orientation ofparticular cross-sectional views.

FIG. 5 b shows a downward view of nut restrainer 101 with cap 108 (shownin at least FIG. 5 a ) not present, and nut 120 included. Top plane 102,nut space sidewalls 103, and restrainer central axis 130 are also shown.The location of section cut plane B is shown in FIG. 5 b , and is usedin subsequent figures to identify the orientation of particularcross-sectional views.

FIG. 5 c shows a downward cross-sectional view of nut restrainer 101with washer 121 included. The cross section shown in FIG. 5 c is cutthrough washer space sidewalls 104 of nut restrainer 101. The relativelocations of washer space sidewalls 104, washer 121, and restrainercentral axis 130 are shown. The location of section cut plane B is shownin FIG. 5 c , and is used in subsequent figures to identify theorientation of particular cross-sectional views.

FIG. 5 d shows a downward cross-sectional view of nut restrainer 101with nut 120 inserted. The cross section shown in FIG. 5 d is cutthrough nut space sidewalls 103 and removable nut centering elements 106of nut restrainer 101. As shown in FIG. 5 d , removable nut centeringelements 106 are configured to hold nut 120 substantially concentricwith nut restrainer 101 while cap 108 (shown in at least FIG. 5 a ) isattached to the balance of nut restrainer 101. The relative locations ofnut restrainer central axis 130 and cavity 133 are also shown. Thelocation of section cut plane B is shown in FIG. 5 d , and is used insubsequent figures to identify the orientation of particularcross-sectional views.

FIG. 5 e shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 5 e isindicated by section B, as shown in at least FIG. 5 a . The relativelocations of top plane 102, nut space sidewalls 103, washer spacesidewalls 104, removable nut centering elements 106, cap 108, snap-onprotrusions 109, and restrainer central axis 130 are also shown.

FIG. 6 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 6 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 6 b shows the embodiment after installation of thefastening bolt. FIG. 6 a shows a transverse cross-sectional view of nutrestrainer 101 and other relevant elements at the moment of affixment tosubstrate plate 122. The location and direction of the cross sectionalview through nut restrainer 101 shown in FIG. 6 a is indicated bysection B, as shown in at least FIG. 5 a . As shown in FIG. 6 a , theshank of centering bolt 125 is in contact with the walls of substratebolt hole 123, so that substrate bolt hole central axis 131 andrestrainer central axis 130 are offset by a distance substantially equalto the radial tolerance of the bolt hole. As shown in FIG. 6 a , in someembodiments, centering bolt 125 is shorter than fastening bolt 126(shown in at least FIG. 6 b ) because centering bolt 125 extendingbeyond nut 120 during the process of locating and affixing nutrestrainer 101 to substrate plate 122 could dislodge cap 108 before nutrestrainer 101 is affixed to substrate plate 122. In other embodimentsof the invention, the distance from substrate plate 122 to top plane 102may be larger than that shown in FIG. 6 a , allowing centering bolt 125to extend beyond nut 120 without dislodging cap 108. The relativelocations of removable nut centering element 106 and washer 121 are alsoshown.

FIG. 6 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 6 b is indicated by section B, as shown inat least FIG. 5 a . As shown in FIG. 6 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, the nut space must provide freedom ofmovement to the nut equal to at least two times the radial tolerance ofthe bolt hole in all lateral directions. The relative locations of topplane 102, nut 120, washer 121, substrate plate 122, are also shown.

FIGS. 7, 8 and 9 show various views of an exemplary embodiment of theinvention. FIGS. 7 a and 7 b show three-dimensional views of theembodiment in isolation. FIGS. 7 c and 7 d show elements of theembodiment in isolation to present aspects of the embodiment that arenot easily visible when the embodiment is shown in its entirety. FIG. 7a shows a three-dimensional view of nut restrainer 101 from the top andside. The relative locations of top plane 102, viewports 107, and cap108 are shown.

FIG. 7 b shows a three-dimensional view of nut restrainer 101 from thebottom and side. FIG. 7 b shows cap 108 with deformable nut centeringelements 105 that extend into the cavity of nut restrainer 101 to holdnut 120 (shown in at least FIG. 9 b ) substantially concentric with nutrestrainer 101 prior to insertion of fastening bolt 126 (shown in atleast FIG. 9 b ). Deformable nut centering elements 105 are formed andproportioned to be flexible compared to the balance of nut restrainer101, allowing nut 120 to move in a lateral direction to accept fasteningbolt 126 if fastening bolt 126 is inserted into nut restrainer 101non-concentrically with respect to nut restrainer 101. Unlike theembodiment shown in FIGS. 4 through 6 , the embodiment shown in FIG. 7 bdoes not require cap 108 to be removed prior to installation offastening bolt 126. As shown in FIG. 7 b , nut space sidewalls 103include three recesses that allow deformable nut centering elements 105to move in a lateral direction a distance of at least two times theradial tolerance of the bolt hole. The relative locations of top plane102, washer space sidewalls 104, viewports 107, and snap-on protrusions109 are also shown.

FIG. 7 c shows a three-dimensional view of nut restrainer 101 (shown inits entirety in at least FIG. 7 a ) from the top and side with cap 108(shown in at least FIG. 7 d ) not present. As shown in FIG. 7 c , topplane 102 has four openings. The three smaller openings providelocations where deformable nut centering elements 105 (shown in at leastFIG. 7 b ) of cap 108 can be inserted into the cavity of nut restrainer101. The larger opening in the center of top plane 102 serves at leasttwo purposes. First, it allows the tip of fastening bolt 126 (shown inat least FIG. 9 b ) to pass through top plane 102 in cases wherefastening bolt 126 extends past nut 120 (shown in at least FIG. 9 b ) inthe final configuration. Second, the non-circular shape of the largeropening, which corresponds to the shape of snap-on protrusions 109(shown in at least FIG. 7 d ), ensures that cap 108 may only be snappedinto place in a position where deformable nut centering elements 105pass through the three small openings in top plane 102, hold nut 120substantially concentric with nut restrainer 101, and correspond to therecesses in nut space sidewalls 103. If the large opening in top plane102 were circular, cap 108 could be snapped into place with anorientation whereby deformable nut centering elements 105 are notcentered with respect to the three small openings in top plane 102,potentially resulting in deformable nut centering elements 105 beingunable to move in a particular lateral direction due to obstruction bynut space sidewalls 103 (shown in at least FIG. 7 b ). The relativelocation of viewport 107 is also shown.

FIG. 7 d shows a three-dimensional view of cap 108 in isolation from thebottom and side. As shown in FIG. 7 d , cap 108 has at least fourcritical features: first, deformable nut centering elements 105 aredimensioned and arranged to engage with at least three sides of nut 120(shown in at least FIG. 9 b ), holding nut 120 substantially concentricwith nut restrainer 101 (shown in its entirety in at least FIG. 7 a )prior to the insertion of fastening bolt 126 (shown in at least FIG. 9 b). Second, snap-on protrusions 109 are configured such that cap 108 maybe snapped into place atop nut restrainer 101, engaging with top plane102 (shown in at least FIG. 7 b ). Third, top plane 102 and snap-onprotrusions 109 are configured to ensure that cap 108 may only besnapped into place in a position from which deformable nut centeringelements 105 hold nut 120 concentric with nut restrainer 101, and fromwhich deformable nut centering elements 105 can deform as required toprovide nut 120 freedom of movement substantially equal to at least twotimes the radial tolerance of the bolt hole. Fourth, deformable nutcentering elements 105 are formed and proportioned to be flexiblecompared to the balance of nut restrainer 101, thus enabling nut 120 tomove in a lateral direction to accept fastening bolt 126, if fasteningbolt 126 is inserted into nut restrainer 101 non-concentrically with nutrestrainer 101.

FIG. 8 shows downward and cross sectional views of an embodiment of theinvention, FIG. 8 a shows a downward view of the embodiment inisolation. FIG. 8 b shows a downward view of the embodiment withhardware included and the cap omitted. FIGS. 8 c, 8 d and 8 e show crosssections of the embodiment with hardware included. FIG. 8 a shows adownward view of nut restrainer 101 including cap 108. The relativelocations of nut space sidewalls 103, deformable nut centering elements105, snap-on protrusions 109, and restrainer central axis 130 are alsoshown. The location of section cut plane C is shown in FIG. 8 a , and isused in subsequent figures to identify the orientation of particularcross-sectional views.

FIG. 8 b shows a downward view of nut restrainer 101 with cap 108 (shownin at least FIG. 8 a ) not present and nut 120 included. The relativelocations of top plane 102, nut space sidewalls 103, and restrainercentral axis 130 are also shown. The location of section cut plane C isshown in FIG. 8 b , and is used in subsequent figures to identify theorientation of particular cross-sectional views.

FIG. 8 c shows a downward cross-sectional view of nut restrainer 101with washer 121 included. The cross section shown in FIG. 8 c is cutthrough washer space sidewalls 104 of nut restrainer 101. The relativelocations of viewport 107, and restrainer central axis 130 are alsoshown. The location of section cut plane C is shown in FIG. 8 c , and isused in subsequent figures to identify the orientation of particularcross-sectional views.

FIG. 8 d shows a downward cross-sectional view of nut restrainer 101with nut 120 inserted. The cross section shown in FIG. 8 d is cutthrough nut space sidewalls 103 of nut restrainer 101. As shown in FIG.8 d , deformable nut centering elements 105 are sufficiently stiff andstrong to hold nut 120 substantially concentric with nut restrainer 101when no force acting on nut 120 in a lateral direction exceeds themagnitude of the force imposed on nut 120 by gravity. In cases wherefastening bolt 126 (shown in at least FIG. 9 b ) is inserted into nutrestrainer 101 non-concentrically with nut restrainer 101, interactionbetween the tip of fastening bolt 126 and nut 120 will cause nut 120 todisplace laterally, pushing one or more deformable nut centeringelements 105 into the recesses formed by nut space sidewalls 103 in thisembodiment of the invention. The relative locations of restrainercentral axis 130, and cavity 133 are also shown. The location of sectioncut plane C is shown in FIG. 8 d , and is used in subsequent figures toidentify the orientation of particular cross-sectional views.

FIG. 8 e shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 8 e isindicated by section C, as shown in at least FIG. 8 a . The relativelocations of top plane 102, nut space sidewalls 103, deformable nutcentering elements 105, viewport 107, cap 108, snap-on protrusions 109,and restrainer central axis 130 are also shown.

FIG. 9 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 9 a shows the embodiment at the moment of affixment to thesubstrate plate. FIG. 9 b shows the embodiment during installation ofthe fastening bolt, FIG. 9 c shows the embodiment after installation ofthe fastening bolt. FIG. 9 a shows a transverse cross-sectional view ofnut restrainer 101 and other relevant elements at the moment ofaffixment to substrate plate 122. The location and direction of thecross sectional view through nut restrainer 101 shown in FIG. 9 a isindicated by section C, as shown in at least FIG. 8 a . As shown in FIG.9 a , the shank of centering bolt 125 is in contact with the walls ofsubstrate bolt hole 123, so that substrate bolt hole central axis 131and restrainer central axis 130 are offset by a distance substantiallyequal to the radial tolerance of the bolt hole. As shown in FIG. 9 a ,in some embodiments, centering bolt 125 is shorter than fastening bolt126 (shown in at least FIG. 9 b ) because centering bolt 125 extendingbeyond nut 120 during the process of locating and affixing nutrestrainer 101 to substrate plate 122 could dislodge cap 108 before nutrestrainer 101 is affixed to substrate plate 122. In other embodimentsof the invention, the distance from substrate plate 122 to top plane 102may be larger than that shown in FIG. 9 a , allowing centering bolt 125to extend beyond nut 120 without dislodging cap 108. The relativelocations of deformable nut centering element 105, and washer 121 arealso shown.

FIG. 9 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements during installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 9 b is indicated by section C, as shown inat least FIG. 8 a . As shown in FIG. 9 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, deformable nut centering elements 105 mustbe sufficiently flexible to deform when a force in a lateral directionacts on nut 120 due to interaction between nut 120 and the tip offastening bolt 126, and the nut space must be shaped to provide nut 120freedom of movement substantially equal to at least two times the radialtolerance of the bolt hole in all lateral directions, while not impedingthe deformation of deformable nut centering elements 105. Thedeformation of deformable nut centering elements 105 due to movement ofnut 120 in a lateral direction is visible in FIG. 9 b as a change inshape and location of deformable nut centering element 105 relative tothat shown in FIG. 9 a . The relative locations of top plane 102, cap108, washer 121, and substrate plate 122 are also shown.

FIG. 9 c shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 9 c is indicated by section C, as shown inat least FIG. 8 a , As shown in FIG. 9 c , the tip of fastening bolt 126has protruded past nut 120 and dislodged cap 108 from the balance of nutrestrainer 101. The relative locations of top plane 102, washer 121,substrate plate 122, substrate bolt hole 123, fastened plate 124,restrainer central axis 130, substrate bolt hole central axis 131, andfastening bolt central axis 132 are also shown.

FIGS. 10, 11 and 12 show various views of an exemplary embodiment of theinvention. FIGS. 10 a and 10 b show three-dimensional views of theembodiment in isolation. FIG. 10 a shows a three-dimensional view of nutrestrainer 101 from the top and side. Nut restrainer 101 as shown inFIG. 10 is an embodiment well-suited to production by means of metalstamping, having a geometry that can be created by cutting and foldingan initially flat piece of material. Deformable nut centering elements105 comprise a pair of protrusions emanating from top plane 102 of nutrestrainer 101. Each deformable nut centering element 105 ends in aU-shaped tip extending into the cavity of nut restrainer 101. When nut120 (shown in at least FIG. 12 b ) is inserted into nut restrainer 101,the tips of the deformable nut centering elements 105 engage four of thesix sides of nut 120, holding nut 120 substantially concentric with nutrestrainer 101 prior to insertion of fastening bolt 126 (shown in atleast FIG. 12 b ). If fastening bolt 126 is inserted into nut restrainer101 non-concentrically with nut restrainer 101, deformable nut centeringelements 105 will bend or twist, allowing nut 120 to move in a lateraldirection to accept fastening bolt 126. The embodiment shown in FIG. 10a includes washer centering elements 110, which hold washer 121 (shownin at least FIG. 12 b ) substantially concentric with nut restrainer 101prior to insertion of fastening bolt 126. Similar to deformable nutcentering elements 105, washer centering elements 110 are flexiblecompared to the balance of nut restrainer 101, allowing washer 121 tomove in a lateral direction to accept fastening bolt 126 if fasteningbolt 126 is inserted into nut restrainer 101 non-concentrically with nutrestrainer 101. Embodiments that include washer centering elements 110are preferable to embodiments that allow washer 121 to move freelywithin the washer space because the maximum possible misalignmentbetween the central axis of washer 121 and fastening bolt central axis132 (shown in at least FIG. 12 b ) when fastening bolt 126 is insertedinto nut restrainer 101 is reduced by the presence of washer centeringelements 110. The embodiment shown in FIG. 10 a includes washer cutout111 to allow nut restrainer 101 to accept insertion of washer 121. Therelative location of nut space sidewalls 103 is also shown.

FIG. 10 b shows a three-dimensional view of nut restrainer 101 from thebottom and side. The relative locations of top plane 102, nut spacesidewalls 103, deformable nut centering elements 105, washer centeringelements 110, and washer cutout 111, are shown.

FIG. 11 shows downward and cross sectional views of an embodiment of theinvention. FIG. 11 a shows a downward view of the embodiment inisolation. FIGS. 11 b, 11 c, 11 d and 11 e show cross sections of theembodiment with hardware included. FIG. 11 a shows a downward view ofnut restrainer 101 in isolation. The relative locations of top plane102, nut space sidewalls 103, deformable nut centering elements 105,washer centering elements 110, washer cutout 111, and restrainer centralaxis 130 are shown. The location of section cuts planes D and E areshown in FIG. 11 a , and are used in subsequent figures to identify theorientation of particular cross-sectional views.

FIG. 11 b shows a downward cross-sectional view of nut restrainer 101with washer 121 included. The cross section shown in FIG. 11 b is cutthrough washer centering elements 110 of nut restrainer 101. Therelative locations of nut space sidewalls 103, washer cutout 111 andrestrainer central axis 130 are also shown. The location of section cutsplanes D and E are shown in FIG. 11 b , and are used in subsequentfigures to identify the orientation of particular cross-sectional views.

FIG. 11 c shows a downward cross-sectional view of nut restrainer 101with nut 120 inserted. The cross section shown in FIG. 11 c is cutthrough nut space sidewalls 103 and deformable nut centering elements105 of nut restrainer 101. As shown in FIG. 11 c , deformable nutcentering elements 105 are configured to hold nut 120 substantiallyconcentric with nut restrainer 101 when no force acting on nut 120 in alateral direction exceeds the magnitude of the force imposed on nut 120by gravity. In cases where fastening bolt 126 (shown in at least FIG. 12b ) is inserted into nut restrainer 101 non-concentrically with nutrestrainer 101, interaction between the tip of fastening bolt 126 andnut 120 will cause nut 120 to displace laterally, bending or twistingone or more deformable nut centering elements 105, and allowingfastening bolt 126 to be tightened with nut 120. Deformable nutcentering elements 105 are preferably configured so that deformable nutcentering elements 105 must move away from the restrainer central axis130 to accommodate insertion of nut 120. Requiring deformable nutcentering elements 105 to move outwards to accommodate nut 120 ensuresthat nut 120 is held in snug contact with deformable nut centeringelements 105, and substantially concentric with nut restrainer 101, evenin cases where manufacturing inaccuracies result in nut 120 beingsmaller than its theoretical dimensions. The relative location of cavity133 is also shown. The location of section cut planes D and E are shownin FIG. 11 c , and are used in subsequent figures to identify theorientation of particular cross-sectional views.

FIG. 11 d shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 11 d isindicated by section D, as shown in at least FIG. 11 a . The relativelocations of top plane 102, washer centering elements 110, andrestrainer central axis 130 are also shown.

FIG. 11 e shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 11 e isindicated by section E, as shown in at least FIG. 11 a . The relativelocations of top plane 102, nut space sidewalls 103, washer cutout 111,and restrainer central axis 130 are also shown.

FIG. 12 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 12 a shows the embodiment at the moment of affixment tothe substrate plate. FIGS. 12 b and 12 c show the embodiment afterinstallation of the fastening bolt. FIG. 12 a shows a transversecross-sectional view of nut restrainer 101 and other relevant elementsat the moment of affixment to substrate plate 122. The location anddirection of the cross sectional view through nut restrainer 101 shownin FIG. 12 a is indicated by section E, as shown in at least FIG. 11 a ,As shown in FIG. 12 a , the shank of centering bolt 125 is in contactwith the walls of substrate bolt hole 123, so that substrate bolt holecentral axis 131 and restrainer central axis 130 are offset by adistance substantially equal to the radial tolerance of the bolt hole.In some embodiments, centering bolt 125 and fastening bolt 126 (shown inat least FIG. 12 b ) may be the same bolt. However, in other cases, thelengths of threaded and unthreaded portions (if present) of the shank offastening bolt 126 may prevent fastening bolt 126 from being broughtinto snug contact with nut 120 in the absence of fastened plate 124(shown in at least FIG. 12 b ), necessitating the use of a distinct boltas centering bolt 125. The relative locations of top plane 102 andwasher 121 are also shown.

FIG. 12 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 12 b is indicated by section E, as shown inat least FIG. 11 a . As shown in FIG. 12 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, deformable nut centering elements 105(shown in at least FIG. 12 c ) must be sufficiently flexible to deformwhen a force in a lateral direction acts on nut 120 due to interactionbetween nut 120 and the tip of fastening bolt 126, and the nut spacemust be shaped to provide nut 120 freedom of movement substantiallyequal to at least two times the radial tolerance of the bolt hole in alllateral directions. The relative locations of top plane 102, washer 121,and substrate plate 122 are also shown.

FIG. 12 c shows a downward cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126. Asshown in FIG. 12 c , nut 120 has moved in a lateral direction to acceptinsertion of fastening bolt 126, causing deformable nut centeringelements 105 to bend and twist. The relative locations of nut spacesidewalls 103, restrainer central axis 130, fastening bolt central axis132 are also shown.

FIGS. 13, 14 and 15 show various views of exemplary embodiments of theinvention, FIGS. 13 a and 13 b each show a three-dimensional view of anembodiment of the invention in isolation. FIGS. 14 and 15 show otherviews of the embodiment shown in FIG. 13 a . Whereas the embodiments ofthe invention shown in FIGS. 1 through 12 allow the nut to move withinthe cavity of the nut restrainer to accept the fastening bolt when thefastening bolt is inserted non-concentrically with the nut restrainer,the embodiments shown in FIGS. 13 through 15 (as well as FIGS. 16through 19 ) allow the cavity, and the nut inserted therein, to move sothat the nut can accept the fastening bolt if the fastening bolt isinserted into the nut restrainer non-concentrically with the nutrestrainer. As shown in FIG. 13 a , nut restrainer 101 includes mobilecentral portion 112 that is joined to rigid outer portion 113 by meansof flexible connectors 114. Flexible connectors 114 are slender and bentaway from substrate plate 122 (shown in at least FIG. 15 b ), makingthem flexible in all lateral directions compared to the balance of nutrestrainer 101. If fastening bolt 126 is inserted into nut restrainer101 non-concentrically with nut restrainer 101, flexible connectors 114will bend or twist, thus allowing mobile central portion 112, nut 120(shown in at least FIG. 15 b ) and washer 121 (shown in at least FIG. 15b ) restrained within mobile central portion 112, to move laterally withrespect to rigid outer portion 113, and accept fastening bolt 126. Rigidouter portion 113 is formed so that no portion of rigid outer portion113 impedes movement of mobile central portion 112 in any lateraldirection within two times the tolerance of the bolt hole from theequilibrium position of mobile central portion 112. Embodiments thatinclude mobile central portion 112 (including those shown in FIGS. 13through 19 ) may have the advantage of more tightly confining nut 120within the nut space, and thus more effectively rotationally restrainingnut 120, even when nut 120 is subjected to high magnitudes of torqueduring the installation of fastening bolt 126, than embodiments(including those shown in FIGS. 1 through 12 ) that allow nut 120 tomove within the cavity of nut restrainer 101. The relative locations oftop plane 102, nut space sidewalls 103, and weld location indicator 118are also shown.

FIG. 13 b shows an embodiment of nut restrainer 101 similar to thatshown in FIG. 13 a , except that the comparative flexibility of flexibleconnectors 114 is attributable to a tortuous path, rather than beingbent away from substrate plate 122 (shown in at least FIG. 15 b ). Theembodiment shown in FIG. 13 b may be cheaper to produce that that shownin FIG. 13 a because flexible connectors 114 are coplanar with rigidouter portion 113. In both the embodiments shown in FIGS. 13 a and 13 b, mobile central portion 112, rigid outer portion 113, and flexibleconnectors 114 are formed such that flexible connectors 114 willelongate, and become increasingly stiff with respect to rotation aboutrestrainer central axis 130 (shown in at least FIG. 15 b ) as torque isapplied to the nut in the direction associated with the tightening offastening bolt 126 (shown in at least FIG. 15 b ) with nut 120 (shown inat least FIG. 15 b ). Flexible connectors 114 are proportioned to besufficiently strong to resist the maximum torque that is anticipated tobe transferred to mobile central portion 112 during the process oftightening fastening bolt 126 with nut 120. The relative locations oftop plane 102, nut space sidewalls 103, and weld location indicator 118are also shown.

FIG. 14 shows downward and cross sectional views of an embodiment of theinvention. FIG. 14 a shows a downward view of the embodiment withhardware included. FIGS. 14 b, 14 c, and 14 d show cross sections of theembodiment with hardware included. FIG. 14 a shows a downward view ofnut restrainer 101 with nut 120 included. As shown in FIG. 14 a , rigidouter portion 113 includes weld location indicators 118, which show theuser a suggested location for affixing (by way of non-limiting example,in this embodiment by welding) rigid outer portion 113 to substrateplate 122 (shown in at least FIG. 15 b ). When torque is applied tomobile central portion 112 by tightening fastening bolt 126 (shown in atleast FIG. 15 b ) with nut 120, flexible connectors 114 will transmitforce in tension between mobile central portion 112 and outer rigidouter portion 113. Weld location indicators 118 are located along thecenterline of flexible connectors 114 so that force is transmitted fromflexible connectors 114 to the points of affixment to substrate plate122 without inducing bending in rigid outer portion 113, therebyreducing the amount of material required to make rigid outer portion 113sufficiently rigid. The relative locations of top plane 102, nut spacesidewalls 103, washer space sidewalls 104, and restrainer central axis130 are shown. The location of section cut plane F is shown in FIG. 14 a, and is used in subsequent figures to identify the orientation ofparticular cross-sectional views.

FIG. 14 b shows a downward cross-sectional view of nut restrainer 101with washer 121 included. The cross section shown in FIG. 14 b is cutthrough washer space sidewalls 104 of nut restrainer 101. Minimizing, tothe greatest extent practical, the possible movement of washer 121 inany lateral direction within the washer space prior to insertion offastening bolt 126 (shown in at least FIG. 15 b ) may enhance theperformance of nut restrainer 101 because it reduces the maximumpossible misalignment between the central axis of washer 121 andfastening bolt central axis 132 (shown in at least FIG. 15 b ) whenfastening bolt 126 is inserted into nut restrainer 101. One way toreduce the possible movement of washer 121 within the washer space is toreduce the diameter of the washer space for a given size of washer 121.The washer spaces in embodiments (such as those shown in FIGS. 13through 19 ) that include mobile central portion 112 (shown in at leastFIG. 13 a ) may have smaller diameters for a given size washer 121 thanin the embodiments (such as those shown in FIGS. 1 through 12 ) withoutmobile central portion 112, because embodiments including mobile centralportion 112 do not require washer 121 to be able to move within thewasher space to accept fastening bolt 126 (shown in at least FIG. 15 b )if fastening bolt 126 is inserted into nut restrainer 101non-concentrically with nut restrainer 101. A second way, to reduce thepossible movement of the washer in any lateral direction prior toinsertion of the fastening bolt is to include washer centering elements,as in the embodiment shown in FIGS. 10 through 12 , The relativelocation of restrainer central axis 130 is also shown. The location ofsection cut plane F is shown in FIG. 14 b , and is used in subsequentFigures to identify the orientation of particular cross-sectional views.

FIG. 14 c shows a downward cross-sectional view of nut restrainer 101with nut 120 included. The cross section shown in FIG. 14 c is cutthrough nut space sidewalls 103 of nut restrainer 101. Minimizing, tothe greatest extent practical, the interior dimensions of the nut spacemay enhance the performance of nut restrainer 101 because the moretightly confined nut 120 is within the nut space, the less likely nut120 is to mar or otherwise damage nut space sidewalls 103 when subjectedto torque due to the tightening of fastening bolt 126 (shown in at leastFIG. 15 b ) with nut 120. The nut space in embodiments (such as thoseshown in FIGS. 13 through 19 ) that include mobile central portion 112(shown in at least FIG. 13 a ) may have a smaller interior dimensionsfor a given size nut 120 than in embodiments (such as those shown inFIGS. 1 through 12 ) without mobile central portion 112, becauseembodiments that include mobile central portion 112 do not require nut120 to be able to move within the nut space to accept fastening bolt 126if fastening bolt 126 is inserted into nut restrainer 101non-concentrically with nut restrainer 101. The relative locations ofrestrainer central axis 130 and cavity 133 are also shown. The locationof section cut plane F is shown in FIG. 14 c , and is used in subsequentfigures to identify the orientation of particular cross-sectional views.

FIG. 14 d shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 inserted. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 14 d isindicated by section F, as shown in at least FIG. 14 a . The relativelocations of top plane 102, nut space sidewalls 103, washer spacesidewalls 104, mobile central portion 112, rigid outer portion 113,flexible connectors 114, and restrainer central axis 130 are also shown.

FIG. 15 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 15 a shows the embodiment at the moment of affixment tothe substrate plate. FIG. 15 b shows the embodiment after installationof the fastening bolt. FIG. 15 a shows a transverse cross-sectional viewof nut restrainer 101 and other relevant elements at the moment ofaffixment to substrate plate 122. The location and direction of thecross sectional view through nut restrainer 101 shown in FIG. 15 a isindicated by section F, as shown in at least FIG. 14 a , As shown inFIG. 15 a , the shank of centering bolt 125 is in contact with the wallsof substrate bolt hole 123, so that substrate bolt hole central axis 131and restrainer central axis 130 are offset by a distance substantiallyequal to the radial tolerance of the bolt hole. In some embodiments,centering bolt 125 and fastening bolt 126 (shown in at least FIG. 15 b )may be the same bolt. However, in other cases, the lengths of threadedand unthreaded portions (if present) of the shank of fastening bolt 126may prevent fastening bolt 126 from being brought into snug contact withnut 120 in the absence of fastened plate 124 (shown in at least FIG. 15b ), necessitating the use of a distinct bolt as centering bolt 125. Therelative locations of top plane 102, mobile central portion 112, rigidouter portion 113, flexible connectors 114, and washer 121 are alsoshown.

FIG. 15 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 15 b is indicated by section F, as shown inat least FIG. 14 a . As shown in FIG. 15 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, flexible connectors 114 must besufficiently flexible to deform when a lateral force is imposed on nut120 due to interaction between nut 120 and the tip of fastening bolt126. Deformation of flexible connectors 114 due to lateral movement ofnut 120 is visible in FIG. 15 b as a change in the size of the gapseparating mobile central portion 112 from rigid outer portion 11compared to the gap shown in FIG. 15 a . The relative locations of topplane 102, washer 121, substrate plate 122, are also shown.

FIGS. 16, 17 and 18 show various views of an exemplary embodiment of theinvention, FIGS. 16 a and 16 b show three-dimensional views of theembodiment in isolation. FIGS. 16 c and 16 d show elements of theembodiment in isolation to present aspects of the embodiment that arenot easily visible when the embodiment is shown in its entirety. FIG. 16a shows a three-dimensional view of nut restrainer 101 from the top andside in isolation. Whereas the embodiments of the nut restrainerpresented in FIGS. 13 through 15 , include a mobile central portioncontiguous with a rigid outer portion, and joined by flexibleconnectors, the embodiment shown in FIGS. 16 through 18 comprises mobilecentral portion 112 and rigid outer portion 113 that are distinctportions of material, with mobile central portion 112 held in place byrigid outer portion 113, Mobile central portion 112 accepts insertion ofnut 120 (shown in at least FIG. 18 b ) and washer 121 (shown in at leastFIG. 18 b ), and rotationally restrains nut 120 within the nut space,Rigid outer portion 113 includes deformable protrusions 116, which areconfigured so that the tips of deformable protrusions 116 are in snugcontact with mobile central portion 112. As shown in FIG. 16 a ,deformable protrusions 116 engage three of the six flat exterior sidesof mobile central portion 112 (though other embodiments where the mobilecentral portion does not have flat exterior sides are also envisioned),holding mobile central portion 112 substantially concentric with rigidouter portion 113 when no force in any lateral direction acting on nut120, washer 121 or mobile central portion 112 has a magnitude exceedingthe magnitude of the force acting on the respective elements due togravity. Deformable protrusions 116 are formed and proportioned to besufficiently flexible to deform when a lateral force is imposed on nut120 due to an interaction between nut 120 and the tip of fastening bolt126 (shown in at least FIG. 18 b ), allowing nut 120, washer 121, andmobile central portion 112 to move laterally to accept fastening bolt126 if fastening bolt 126 is inserted into nut restrainer 101non-concentrically with nut restrainer 101. Rigid outer portion 113 isconfigured so that no portion of rigid outer portion 113 impedes thelateral movement of mobile central portion 112 within two times theradial tolerance of the bolt hole in any direction from the equilibriumposition of mobile central portion 112. The relative locations of topplane 102, nut space sidewalls 103, radial protrusions 115, raisedhold-downs 117, and weld location indicators 118 are also shown.

FIG. 16 b shows a three-dimensional view of nut restrainer 101 from thebottom and side in isolation. Mobile central portion 112 includes radialprotrusions 115. Rigid outer portion 113 includes raised hold-downs 117that are not in contact with substrate plate 122 (shown in at least FIG.18 b ) after affixment of nut restrainer 101 to substrate plate 122. Thespaces between raised hold-downs 117 and substrate plate 122 constituterecesses into which radial protrusions 115 of mobile central portion 112fit. Confinement of radial protrusions 115 between raised hold-downs 117and substrate plate 122 rotationally restrains mobile central portion112, and prevents mobile central portion 112 from moving away fromsubstrate plate 122 if nut 120 (shown in at least FIG. 18 b ) is actedon by a force perpendicular to the face of substrate plate 122 due tothe insertion of fastening bolt 126 (shown in at least FIG. 18 b )through substrate bolt hole 123 (shown in at least FIG. 18 b ). Therelative locations of nut space sidewalls 103, washer space sidewalls104, and weld location indicator 118 are also shown.

FIG. 16 c shows a three-dimensional view of mobile central portion 112from the top and side in isolation. The relative locations of top plane102, nut space sidewall 103, and radial protrusions 115 are shown,

FIG. 16 d shows a three-dimensional view of rigid outer portion 113 fromthe top and side in isolation. Rigid outer portion 113 includes weldlocation indicators 118, indicating the ideal location for affixing (byway of non-limiting example, in this embodiment by welding) rigid outerportion 113 to substrate plate 122 (shown in at least FIG. 18 b ). Whentorque acts on mobile central portion 112 (shown in at least FIG. 16 a )due to the action of tightening fastening bolt 126 (shown in at leastFIG. 18 b ) with nut 120 (shown in at least FIG. 18 b ), mobile centralportion 112 will tend to rotate counter-clockwise when viewed in thedirection proceeding from top plane 102 (shown in at least FIG. 16 c )to substrate plate 122, until the rotation of mobile central portion 112is impeded by contact between the edges of radial protrusions 115 andraised hold-downs 117 (assuming right-handed threads). By affixing rigidouter portion 113 to substrate plate 122 as close as possible to thelocations where the leading edges of radial protrusions 115 (shown in atleast FIG. 16 c ) contact the edges of raised hold-downs 117, maximumrigidity is achieved, allowing rigid outer portion 113 to be made ofthinner material than would be possible if rigid outer portion 113 wereaffixed to substrate plate 122 at different locations. The relativelocations of deformable protrusions 116 are also shown.

FIG. 17 shows downward and cross sectional views of an embodiment of theinvention with hardware included. FIG. 17 a shows a downward view of theembodiment with hardware included. FIGS. 17 b and 17 c show crosssections of the embodiment with hardware included. 17 a shows a downwardview of nut restrainer 101 with nut 120 included. The relative locationsof top plane 102, nut space sidewalls 103, washer space sidewalls 104,mobile central portion 112, rigid outer portion 113, radial protrusions115, deformable protrusions 116, weld location indicator 118, andrestrainer central axis 130 are also shown. The location of section cutplane G is shown in FIG. 14 a , and is used in subsequent Figures toidentify the orientation of particular cross-sectional views.

FIG. 17 b shows a downward cross-sectional view of nut restrainer 101with nut 120 included. The cross section shown in FIG. 17 b is cutthrough nut space sidewalls 103 of nut restrainer 101. As shown in FIG.17 b , deformable protrusions 116 are configured so that the tips ofdeformable protrusions 116 must move away from restrainer central axis130 to accommodate insertion of mobile central portion 112 (shown in itsentirety in at least FIG. 16 c ) into rigid outer portion 113 (shown inat least FIG. 16 d ), ensuring that mobile central portion 112 is insnug contact with deformable protrusions 116 after mobile centralportion 112 is inserted into rigid outer portion 113. The relativelocation of cavity 133 is also shown. The location of section cut planeG is shown in FIG. 17 b , and is used in subsequent figures to identifythe orientation of particular cross-sectional views.

FIG. 17 c shows a transverse cross-sectional view of nut restrainer 101with nut 120 and washer 121 included. The location and direction of thecross sectional view through nut restrainer 101 as shown in FIG. 17 c isindicated by section G, as shown in at least FIG. 17 a . The relativelocations of top plane 102, nut space sidewalls 103, washer spacesidewalls 104, mobile central portion 112, rigid outer portion 113,radial protrusions 115, deformable protrusions 116, raised hold-downs117, and restrainer central axis 130 are also shown.

FIG. 18 shows cross-sectional views of an embodiment of the inventionwith hardware and other elements present, to show methods of alignmentand use. FIG. 18 a shows the embodiment at the moment of affixment tothe substrate plate. FIG. 18 b shows the embodiment after installationof the fastening bolt. FIG. 18 a shows a transverse cross-sectional viewof nut restrainer 101 and other relevant elements at the moment ofaffixment to substrate plate 122. The location and direction of thecross sectional view through nut restrainer 101 shown in FIG. 18 a isindicated by section G, as shown in at least FIG. 17 a . As shown inFIG. 18 a , the shank of centering bolt 125 is in contact with the wallsof substrate bolt hole 123, so that substrate bolt hole central axis 131and restrainer central axis 130 are offset by a distance substantiallyequal to the radial tolerance of the bolt hole. In some embodiments,centering bolt 125 and fastening bolt 126 (shown in at least FIG. 18 b )may be the same bolt. However, in other cases, the lengths of threadedand unthreaded portions (if present) of the shank of fastening bolt 126may prevent fastening bolt 126 from being brought into snug contact withnut 120 in the absence of fastened plate 124 (shown in at least FIG. 18b ), necessitating the use of a distinct bolt as centering bolt 125. Therelative locations of top plane 102, mobile central portion 112, rigidouter portion 113, radial protrusion 115, deformable protrusion 116,raised hold-down 117 and washer 121 are also shown.

FIG. 18 b shows a transverse cross-sectional view of nut restrainer 101and other relevant elements after installation of fastening bolt 126.The location and direction of the cross sectional view through nutrestrainer 101 shown in FIG. 18 b is indicated by section G, as shown inat least FIG. 17 a . As shown in FIG. 18 b , fastened plate 124 ispositioned such that the shank of fastening bolt 126 is in contact withthe interior of substrate bolt hole 123, resulting in substrate bolthole central axis 131 and fastening bolt central axis 132 being offsetby a distance substantially equal to the radial tolerance of the bolthole. Further, restrainer central axis 130 and fastening bolt centralaxis 132 are offset in substantially opposite directions from substratebolt hole central axis 131, such that restrainer central axis 130 andfastening bolt central axis 132 are offset by a distance substantiallyequal to two times the radial tolerance of the bolt hole. To accommodatethis worst-case misalignment, deformable protrusions 116 must besufficiently flexible to deform when a force in a lateral direction actson nut 120 due to interaction between nut 120 and the tip of fasteningbolt 126. As shown in FIG. 18 b , mobile central portion 112 and itscontents, nut 120 and washer 121, have moved laterally to acceptfastening bolt 126, causing a gap to open between flexible protrusion116 and mobile central portion 112, and causing radial protrusion 115 tomove with respect to raised hold-down 117. The relative locations of topplane 102, rigid outer portion 113, and substrate plate 122, are alsoshown.

FIG. 19 shows various views of exemplary embodiments of the invention.FIG. 19 a shows a three-dimensional view of two joined nut restrainersin isolation according to embodiments of the invention. FIG. 19 b showsa three-dimensional view of an embodiment in isolation. FIGS. 19 c and19 d show elements of the embodiment shown in its entirety in FIG. 19 bin isolation to present aspects of the embodiment that are not easilyvisible when the embodiment is shown in its entirety. FIG. 19 a shows athree-dimensional view of two joined nut restrainers 101 from the topand side in isolation. The nut restrainers 101 are joined to facilitateinstallation of two fastening bolts 126 (shown with respect to a similarembodiment in at least FIG. 18 b ) through adjacent substrate bolt holes123 (shown with respect to a similar embodiment in at least FIG. 18 b )in a single substrate plate 122 (shown with respect to a similarembodiment in at least FIG. 18 b ). Embodiments with more than twojoined nut restrainers in linear, grid or other arrangements are alsoenvisioned. In embodiments with multiple nut restrainers arranged in agrid pattern, the weld location indicators may include holes within thejoined rigid outer portions, in addition to weld location indicators onthe perimeter of the joined rigid outer portion. The relative locationsof top plane 102, nut space sidewalls 103, mobile central portion 112,rigid outer portion 113, radial protrusions 115, weld locationindicators 118, and raised deformable hold-downs 119 are also shown.

FIG. 19 b shows a three-dimensional view of nut restrainer 101 from thetop and side in isolation. The embodiment shown in FIG. 19 b isidentical to that shown in FIG. 19 a , except that nut restrainer 101 inFIG. 19 b is not joined to any additional nut restrainers. Theembodiment shown in FIG. 19 b is similar to that shown in FIGS. 16through 18 , but whereas the embodiment shown in FIGS. 16 through 18 hasdeformable protrusions and raised hold-downs that are distinct portionsof material, the embodiment shown in FIG. 19 b includes several raiseddeformable hold-downs 119, each performing the functions of both theflexible protrusions and the raised portions shown in FIGS. 16 through18 . As shown in FIG. 19 b , radial protrusions 115 and raiseddeformable hold-downs 119 are configured to resist torque applied in thedirection corresponding to tightening fastening bolt 126 (shown withrespect to a similar embodiment in at least FIG. 18 b ) with nut 120(shown with respect to a similar embodiment in at least FIG. 18 b )(assuming right-handed threads). The relative locations of top plane102, nut space sidewalls 103, mobile central portion 112, rigid outerportion 113, and weld location indicators 118 are also shown.

FIG. 19 c shows a three-dimensional view of rigid outer portion 113 fromthe top and side in isolation. As shown in FIG. 19 c , the outside edgeof rigid outer portion 113 is a square with rounded corners andindentations in each of the four edges, the indentations serving as weldlocation indicators 118. In applications requiring multiple fasteningbolts 126 (shown with respect to a similar embodiment in at least FIG.18 b ) in a linear or grid-like arrangement, substrate bolt holes 123(shown with respect to a similar embodiment in at least FIG. 18 b ) maybe spaced at intervals substantially equal to the outer width of rigidouter portion 113, so that weld location indicators 118 of adjacent nutrestrainers 101 (shown in its entirety in at least FIG. 19 b ) coincide,allowing the user to apply weld affixing two nut restrainers 101 tosubstrate plate 122 (shown with respect to a similar embodiment in atleast FIG. 18 b ) with a single motion. Embodiments with weld locationindicators at the corners of the rigid outer portion are alsoenvisioned, and would similarly reduce the amount of welding required toaffix adjacent nut restrainers. The relative locations of raiseddeformable hold-downs 119, are also shown.

FIG. 19 d shows a three-dimensional view of mobile central portion 112from the top and side in isolation. The relative locations of top plane102, nut space sidewalls 103, and radial protrusions 115 are shown.

As will be realized, the systems and methods disclosed herein arecapable of other and different embodiments and its several details maybe capable of modifications in various respects, all without departingfrom the invention as set out in the appended claims. Accordingly, thedrawings and description are to be regarded as illustrative in natureand not in a restrictive or limiting sense with the scope of theapplication being indicated in the claims.

What is claimed:
 1. A nut restrainer for inserting a nut within the nutrestrainer and thereafter affixing the nut restrainer to a substrateplate having two sides, over a bolt hole having a radial tolerance, forsubsequent installation of a bolt having a shank and a tip, from theside of the substrate plate opposite the side to which the nutrestrainer is affixed, the nut restrainer comprising: a portion of oneor more materials formed to define a cavity, and including a top planedisposed away from the substrate plate, and an open end; the cavityconfigured to accept insertion of a nut, with the one or more materialsformed to define the cavity shaped to rotationally restrain the nut, andto include at least one location from which the nut has freedom ofmovement in any lateral direction equal to at least two times the radialtolerance of the bolt hole; the nut restrainer including one or more nutcentering elements comprising one or more portions of removable ordeformable material which extend into the cavity, and which areconfigured to hold the nut in a location from which the nut has freedomof movement in any lateral direction substantially equal to at least twotimes the radial tolerance of the bolt hole, and which may be removed ordeformed so as to no longer extend into the cavity following affixmentof the nut restrainer to the substrate plate, thereby allowing the nutmove in any lateral direction to accept the bolt if the bolt is insertednon-concentrically with respect to the nut; where the nut restrainer isconfigured to prevent escape of the nut from the cavity followingaffixment to the substrate plate; and where no portion of the nutrestrainer prevents direct contact between the nut and the substrateplate, or between the shank of the bolt and either the substrate plateor one or more fastened plates.
 2. A nut restrainer for inserting a nutwithin the nut restrainer and thereafter affixing the nut restrainer toa substrate plate having two sides, over a bolt hole having a radialtolerance, for subsequent installation of a bolt having a shank and atip, from the side of the substrate plate opposite the side to which thenut restrainer is affixed, the nut restrainer comprising: one or morerigid outer portions and a mobile central portion; the mobile centralportion formed to define a cavity, and including a top plane disposedaway from the substrate plate, and an open end; the cavity configured toaccept insertion of a nut, with the material of the mobile centralportion that defines the cavity shaped to rotationally restrain the nut;the one or more rigid outer portions, which include the portions of thenut restrainer that are affixed to the substrate plate, configured sothat the mobile central portion has freedom of movement in any lateraldirection substantially equal to at least two times the radial toleranceof the bolt hole; the one or more rigid outer portions and the mobilecentral portion being connected by one or more flexible connectors,which are sufficiently stiff and strong to substantially preventmovement of the mobile central portion in all lateral directions whenone or more of the nut and the mobile central portion are acted on byforces in any lateral direction with magnitudes not exceeding themagnitude of the force acting on the respective element due to gravity,and sufficiently strong to rotationally restrain the mobile centralportion when the mobile central portion is acted on by a torque due tothe action of tightening the bolt with the nut, and sufficientlyflexible to deform when the nut is acted on by a force in a lateraldirection due to contact between the tip of the bolt and the nut,thereby allowing the nut to move in a lateral direction to accept thebolt if the bolt is inserted non-concentrically with respect to the nut;where the nut restrainer is configured to prevent escape of the nut fromthe cavity following affixment to the substrate plate; and where noportion of the nut restrainer prevents direct contact between the nutand the substrate plate, or between the shank of the bolt and either thesubstrate plate or one or more fastened plates.
 3. A nut restrainer forinserting a nut within the nut restrainer and thereafter affixing thenut restrainer to a substrate plate having two faces, over a bolt holehaving a radial tolerance, for subsequent installation of a bolt havinga shank and a tip, from the side of the substrate plate opposite theside to which the nut restrainer is affixed, the nut restrainercomprising: one or more rigid outer portions and a mobile centralportion; the mobile central portion formed to define a cavity, andincluding a top plane disposed away from the substrate plate, and anopen end; the cavity configured to accept insertion of a nut, with thematerial of the mobile central portion that defines the cavity shaped torotationally restrain the nut; the mobile central portion further havingone or more radial protrusions which extend away from the cavity; theone or more rigid outer portions, which include the portions of the nutrestrainer that are affixed to the substrate plate, having one or moredeformable protrusions, each having a tip; the deformable protrusionsconfigured so that the tips of the deformable protrusions maintaincontact with the mobile central portion prior to insertion of the bolt,and hold the mobile central portion in a location from which the mobilecentral portion has freedom of movement in any lateral directionsubstantially equal to at least two times the radial tolerance of thebolt hole; the deformable protrusions further being sufficiently stiffand strong to substantially prevent movement of the mobile centralportion in all lateral directions when one or more of the nut and themobile central portion are acted on by forces in any lateral directionwith magnitudes not exceeding the magnitude of the force acting on therespective element due to gravity, and being sufficiently flexible todeform when the nut is acted on by a force in a lateral direction due tocontact between the tip of the bolt and the nut, thereby allowing thenut to move in a lateral direction to accept the bolt if the bolt isinserted non-concentrically with respect to the nut; the rigid outerportions further having one or more raised elements that are free fromcontact with the substrate plate, the space between the raised elementsand the substrate plate forming one or more recesses; the recesses andthe radial protrusions of the mobile central portion being configured sothat the radial protrusions fit into the recesses, and so that themobile central portion is rotationally restrained in thecounter-clockwise direction when viewed in a direction proceeding fromthe top plane to the open end, and so that the mobile central portion isprevented from moving away from the face of the substrate plate; wherethe nut restrainer is configured to prevent escape of the nut from thecavity following affixment to the substrate plate; and where no portionof the nut restrainer prevents direct contact between the nut and thesubstrate plate; or between the shank of the bolt and either thesubstrate plate or one or more fastened plates.
 4. A method ofpositioning the nut restrainer of claim 1 concentrically with the bolthole in the substrate plate accurate to within the radial tolerance ofthe bolt hole, the method comprising: inserting the nut into the nutrestrainer; placing the open end of the nut restrainer in flush contactwith the substrate plate, thereby preventing removal of the nut;inserting a bolt from the side of the substrate plate opposite the nutrestrainer, through the bolt hole, and binding the bolt with the nutpreviously inserted into the nut restrainer, so that the bolt and thenut are in snug contact with the substrate plate; affixing the nutrestrainer to the substrate plate; removing the bolt from the nut andwithdrawing the bolt from the bolt hole in the substrate plate.
 5. Amethod of positioning the nut restrainer of claim 2 concentrically withthe bolt hole in the substrate plate accurate to within the radialtolerance of the bolt hole, the method comprising: inserting the nutinto the nut restrainer; placing the open end of the nut restrainer inflush contact with the substrate plate, thereby preventing removal ofthe nut; inserting a bolt from the side of the substrate plate oppositethe nut restrainer, through the bolt hole; and binding the bolt with thenut previously inserted into the nut restrainer, so that the bolt andthe nut are in snug contact with the substrate plate; affixing the nutrestrainer to the substrate plate; removing the bolt from the nut andwithdrawing the bolt from the bolt hole in the substrate plate.
 6. Amethod of positioning the nut restrainer of claim 3 concentrically withthe bolt hole in the substrate plate accurate to within the radialtolerance of the bolt hole, the method comprising: inserting the nutinto the nut restrainer; placing the open end of the nut restrainer inflush contact with the substrate plate, thereby preventing removal ofthe nut; inserting a bolt from the side of the substrate plate oppositethe nut restrainer, through the bolt hole, and binding the bolt with thenut previously inserted into the nut restrainer, so that the bolt andthe nut are in snug contact with the substrate plate; affixing the nutrestrainer to the substrate plate; removing the bolt from the nut andwithdrawing the bolt from the bolt hole in the substrate plate.
 7. Thenut restrainer of claim 1, further wherein the cavity is configured toaccept insertion of a washer in addition to accepting insertion of thenut, and to provide the washer freedom of movement in any lateraldirection at least equal to the radial tolerance of the bolt hole, andto prevent escape of the washer following affixment to the substrateplate.
 8. The nut restrainer of claim 2, further wherein the cavity isconfigured to accept insertion of a washer in addition to acceptinginsertion of the nut, and to provide the washer freedom of movement inany lateral direction at least equal to the radial tolerance of the bolthole, and to prevent escape of the washer following affixment to thesubstrate plate.
 9. The nut restrainer of claim 3, further wherein thecavity is configured to accept insertion of a washer in addition toaccepting insertion of the nut, and to provide the washer freedom ofmovement in any lateral direction at least equal to the radial toleranceof the bolt hole, and to prevent escape of the washer followingaffixment to the substrate plate.
 10. The nut restrainer of claim 1,further wherein the nut restrainer is configured so that the nut isvisible from outside of the nut restrainer following affixment to thesubstrate plate.
 11. The nut restrainer of claim 1, further wherein thecavity defines a substantially equiangular hexagon.
 12. The nutrestrainer of claim 2, further wherein the cavity defines asubstantially regular hexagon.
 13. The nut restrainer of claim 3,further wherein the cavity defines a substantially regular hexagon. 14.The nut restrainer of claim 1, further wherein the nut centeringelements are sufficiently stiff and strong to substantially preventmovement of the nut in all lateral directions when the nut is acted onby a force in any lateral direction with a magnitude not exceeding themagnitude of the force acting on the nut due to gravity, andsufficiently flexible to deform when the nut is acted on by a force in alateral direction due to contact between the tip of the bolt and thenut, thereby allowing the nut to move in a lateral direction within thenut restrainer to accept the bolt when the bolt is insertednon-concentrically the nut.
 15. The nut restrainer of claim 7, furtherwherein the nut restrainer includes one or more washer centeringelements, the washer centering elements comprising: one or more portionsof deformable material, which extend into the cavity of the nutrestrainer, and hold the washer substantially concentric with the nutrestrainer; the washer centering elements being sufficiently stiff andstrong to substantially prevent movement of the washer in all lateraldirections when the washer is acted on by a force in any lateraldirection with a magnitude not exceeding the magnitude of the forceacting on the washer due to gravity, and sufficiently flexible to deformwhen the washer is acted on by a force in a lateral direction due tocontact between the tip of the bolt and the washer, thereby allowing thewasher to move in a lateral direction to accept the bolt if the bolt isinserted non-concentrically with respect to the washer.
 16. The nutrestrainer of claim 1, further wherein the nut centering elements aremade of one or more of foam, cork, rubber, plastic and felt, and thebalance of the nut restrainer is made of metal.
 17. The nut restrainerof claim 1, further wherein the nut centering elements are contiguouswith the balance of the nut restrainer, and the nut centering elements'deformability is attributable to their form and proportioning.
 18. Thenut restrainer of claim 1, further wherein the nut centering elementsare attached to the balance of the nut restrainer using adhesive. 19.The nut restrainer of claim 1, further wherein the nut centeringelements are attached to the balance of the nut restrainer by snappingone or more portions of material that include the nut centering elementsinto place.
 20. The nut restrainer of claim 1, further wherein affixmentof the nut restrainer to the substrate plate is by means of welding.